As Telecom companies assess a transition from 4G to 5G, they have realized that this is more complex than previous transitions. The networks will need to be high density and require huge capital expenditure commitments and coordinated efforts to integrate the ecosystem’s components. Apart from cost optimization, carriers should be building partnerships and strong relationships with vendors, ecosystem partners, regulators, and even competitors in order to tackle myriad operational challenges. The operating model requires reinvention. To realize their ambitions, telcos need to map the new territory and address integration challenges. In order to solve these challenges, the operator community has come together to define Open Radio Access Network (O-RAN) reference architecture to enable next generation Radio Access Network (RAN) infrastructures. Empowered by principles of intelligence and openness, the O-RAN architecture is the foundation for building the virtualized RAN on open hardware, with embedded AI-powered radio control. The architecture is based on well-defined, standardized interfaces to enable an open, interoperable supply chain ecosystem in full support of and complementary to standards promoted by 3GPP as well as other industry standards. The key objective of the O-RAN initiative is to optimize the CAPEX spend on RAN infrastructure and accelerate innovation. While O-RAN embraces disaggregation and openness, it requires strong Software (SW) & Hardware (HW) integration capabilities to create carrier-grade RAN systems.
The impact of 5G on Telcos
RAN | Challenges for 5G Adoption
Decisions on RAN expenditures are considerable, given the large number of tower sites and the need for a revamp of current systems. According to the results of McKinsey’s 2018 5G survey of CTOs of large telcos around the world, 5G rollouts will take until 2022, largely driven by network leadership, customer experience, and capacity expansion.
The forecasted increase in capacity density of 5G networks will result in more capacity per site in RANs, and a far denser grid of 5G base stations. The denser grid allows for the wireless backhaul of data from micro to macro cells since the demand on 5G infrastructure is distributed over many base stations. Therefore, data traversing the network has a shorter distance between the user and destination.
Despite the upside scenario of lower latency and higher throughputs, there are certain challenges that Telcos need to face:
The projected increase in connected devices will mean an increase in potential attack vectors. Until hardware manufacturers and software vendors consolidate standards and create a more mature ecosystem, telcos must facilitate security due-diligence during procurement and patching. A key differentiation will be to guarantee users a certain level of security by collaborating with partners and suppliers.
2. Tower Proliferation
Compared with earlier generations of cellular networking technologies, 5G towers emit higher radio frequencies at shorter wavelengths, which enables greater data throughput at the expense of a more limited range of coverage. For now, service providers are attempting to offer full coverage through increased numbers of base stations and the extension of 5G licenses into lower frequencies within the 5G bands.
There will be a significant expense in installing and maintaining a greater number of base stations, which will in turn be passed down to the consumer. This will prevent an end user from enjoying higher expected cost savings from economies of scale, automation, and service rate competition in the near term.
Current telecommunications network infrastructure requires significant upgrades to keep up with increasing network demand and consequently, operators will be compelled to evaluate new RAN technologies from various providers. Telco companies need to take into consideration how the disaggregation of software and hardware in 5G transport networks will affect their supply chains, as well as RAN virtualization – the deployment of flexible and automated RAN networks that are software-defined and cloud-native. The overall approach will need to be enabled and open by all players for partners to build an interoperable multi-vendor RAN ecosystem.
RAN Commoditization: Industry players form ecosystems and create best practices
Open Radio Access Network or O-RAN is one of the largest industry alliances that transforms the industry toward an open, intelligent, virtualized, and fully interoperable RAN ecosystem. The adoption of this alliance by industry players has made O-RAN the foundation for future RAN.
O-RANs are built on a foundation of virtualized network elements, white-box hardware (since 2019, 17 players have demonstrated seven sets of POCs; field trials have already been started, pushing for commercialization in 2020), AI (targeting more efficient load balancing and improved UX) and standardized interfaces that fully embrace principles of intelligence and openness.
The O-RAN Alliance’s work embodies two core principles:
- Openness is a prerequisite to bring service agility and cloud-scale economics. Open interfaces are essential to enable smaller vendors and operators to introduce their own services or customize the network to suit their own unique needs. Open interfaces also enable multi-vendor deployments, allowing for a more competitive and vibrant supplier ecosystem. Similarly, open source software and hardware reference designs enable faster, more democratic and permission-less innovation. In theory, every architecture component could be open in every sense imaginable, but in practice, it is likely that different components will have varying degrees of openness due to economic and implementation considerations.
- Intelligence is the enabler for dynamic local radio resource allocation and optimizer of network-wide efficiency. Networks will become increasingly complex with 5G. Therefore, they should be able to leverage new learning-based technologies to automate operational network functions and reduce OPEX by leveraging deep-learning techniques to embed intelligence in every layer of the RAN architecture.
The O-RAN Alliance only provides functional compliance to the specifications of components. The requirement of stakeholders is verification, integration, interoperability, and testing of the commoditized RAN components to support a plug-n-play model. Therefore, commoditization of services is not enough; efficient orchestration of the different components is necessary to guarantee stable networks.
Hence, the key success factors for a truly open RAN need to be collaboration under a strong ecosystem and multi-vendor interoperability achieved through solid integration capabilities from a player who leverages experience from RAN R&D and Open Source technologies.
Figure 1. – Summary of goals and challenges